You know, I see stuff like this and find myself disappointed in Jens. This proves he could have made an internal A500 accelerator, he just chose not to. Nope. He just wanted to make a ridiculously expensive "adapter" for his higher-end A1200 accelerators. Completely lazy, if you ask me. 
There are already several internal accelerators for an A500 but only one external (the rare GVP 530), so a new external accelerator is a good choice in my opinion.
This protein board looks nice and indeed the big resistors are definitly A500 spirit.
